In lithography processes for manufacturing semiconductor devices, such as flash memories and Central Processing Units (CPUs), an original writing pattern formed in a mask is transferred to a semiconductor wafer. In recent years, the original writing patterns formed in respective masks are generally written using an electron beam writing apparatus.
When a pattern is written on the mask using an electron beam writing apparatus, deflection electrodes are controlled by voltages applied from a deflection amplifier to focus electron beam on a desired position on the mask. Hence, in order to precisely write a micropattern, a calibration of the deflection amplifier that applies voltages to the deflection electrodes should be carried out before writing the pattern on the mask.